Air preheater for boiler furnaces



1 March 9,1926. 1,576,410 W. M. CONNERY I AIR PREHEATER FORBOILER FURNACES Filed may 22, 1924 'r sheets-sheet 1 ,w29 fr@ March 9., 1926. 4 1,575,410

W. M. CONNERY AIR PREHEATER FOR BOILER FURNACES f Filed may 22, '1924 7 sheets-sheet IVI" Hf 'N i Mmh 9,1926. 1,576,416

, 1 w.M. coNNERY v AIR PREHEATER FOR BOILER FURNACES Filed yMay 22, 1924 7 sheetsheet 4 March 9,1926. Y (576,410

` l W. M. CONNERY AIR PREHEATER FOR BGILER FURNAGES Filed May 22; 1924 rr sheets-sheet 5' March 9 1926.

W. M. CONNERY AIR PREHEATER FOR BOILER FURNACES Filed may 22, 1924 '7 Sheets-$heet 6 March 9 1926. 1 1,576,410

' w. M. CONNERY l AIR PREHEATER FOR BOVIXLER FURNACES VFiled my 22, 1924 7 sheets-Sheet 7' v 'i l w 'To all lwhom z't may concern:

rammed Mar. 9, 1926.

UNITED STATES PATENT#or-"Fica` i vWILLIAM u. cNNnnY, or rHILADELrnIA, PENNSYLVANIA.

AIB `PIBJBHIEA'JTER FOR BOILER FUBNACES.

Application tiled Hay 22,V 1924. Serial No. 715,140.

Be it known that WILLIAM M. CoNNEnr, a citizen ofthe United States of America, residin at Philadelphia, in the county of Philadelphia and State of Pennsylvania,

has invented a new and usefulAir Preheater for Boiler Furnaces, of which the following is a specification. f

There are apparatus for preheating air which is subsequently employed as a draft and injected into boiler furnaces under, into and thirough the fire for creating better `combustion of the fuel and thereb facilitating the heating of the boiler. T es e apparatususe tubes and spaced plates through which the air passes to be heated by t e products of combustion, the air passing through the tubes or between certain of the plates, the products ofacombustion passing around and exteriorly .ofthe tubes or be-J tween certain other of said plates. nIn the constructions using tubes, the tubes corrode and eventually wear away due to the corrosion, necessitating re lacing of the tubes which is expensive an when being lreplaced 1 necessitates the closing down of the plant,

as there has been no construction permitting of the removal of tubes While the apparatus is in operation andiioconstruction permitting. the apparatus to.. function during theA time certain 0f the tubes are removed. In the constructions using plates, up to the present time, no provision has been made to permit certain units or plates' to'be removed and permit the apparatus to@ functionrwith the remaining unitsof plates. Furthermore,

in the constructions which" 'v now employ' spaced plates, no' rovision is present to` Vpositively avoid c o aplsing of the plates or partitions, even thou are usedon the plates.` Thev ribs 'or` anges or fins in these constructions, up to the present time, extend -inthe general 'rection with the passage of the productswof combustion, in which case the passages fol; the products of combustion.

are simply similar to tubes,-hence the plates between the ribsronanges or fins tend to.

collapse. In other words, thereV are no interruptions or staggered relation of the ribs or flanges br fins, Ahence facilitating in \the colla sing l own that just so soon as the plates 4rtions of the- Y of theY plates, and` observation has corrode vand eat away, vthose Y plates between' the ribsv or Fanges .or ns buckle or 'collapse one way orvthe other, in 'which case communication is effected between tlie passages for ainand the passages for the products jof combustion. In other words, the products of combustion enter the air passages and the air enters the passages for the products of combustion which causes a very tpoor operation of a plant employin boiler urnaces.

With the above in view, it is the purpose lof the present invention to cure these defects and disadvantages and in general to provide not only a mechanically but a commercially practical preheating apparatus for boilerfurnaces, a construction which is not only durable but one which will more thoroughly preheat the air`incidental tol its injectionv into the boiler furnace.

Another purpose is vto provide an apparatus of this character using a forced draft and in connection therewith to secure a regenerative use of the lower de ees of` waste heat, such as that passing o to the chimney, for preheating this forced draft the reason thatconsiderable vthought hasl been devoted to the presentinvention lwith the' aim toward producin an a'lpparatus con-l lstlllucted along practica an commercial InY order to permit the preheating a paratus to be re aired without shutting own the plant entirely while repairs are being made, it is a further purpose toemploy a multiple of sections up the re-v heater, each section consisting of a multiple of units and in producing a. construction of -this kind, the invention aims to rmit one or more of the sections to be ea y removed for the repair of. the or to dimmish .the size of the plant. When a section is re- Still further, it is the aim to provide means to permit of inspection of the products of combustion passages in order to as. certain Vwhether or not any of the 'units of any one ofthe sections are/defective. Due

, to the rivets andbolt receiving openings of tions vor plates from collapsing.

the various parts used in the construction of this present type of apparatus, corresponding and registering not only in construction but also in location, the end wall of such a .preheater may be easily moved up -when a section of units is removed.

' I A still further purpose is to provide, in

a .construction of preheating apparatus, an arrangement of collapsibility preventing members upon the adjacent plates or division walls, said members being staggered and alternating or, in other words, some extending incertain directions and intermediatc members extending' in opposite directions. It has been found that a construction of this kind will prevent theespaced parti- In construction each section is made vup of a number of cellular units or cells, these being spaced to provide passages between them for'the hot products of combustion while each cell; itself, constitutes a thin flat passage for the air during the heat- -ing operation. Moreover, at each end of each section there is provided a frame `or boxing which includes a removable front plate and the sections, with their frames or boxings are individually removable 'from the entire apparatus.

In preheaters heretofore devised," no provision ,exists for removing the soot, scale and collection of matter on the walls of the prod- @ucts of combustion passages, hence the pres.-

ent invention'contemplatcs the provision of means for injectingcompressed air. blasts through the products of combustion passages downwardly from above and from apoint approximating closely to the lower portions of the passages. Obviously, .one 'or the other of these1 compressed air blastdevices, preferabl'f the lower one, vmay be dispensed with, i foundl practical for usein connection -with a plant wherein the' present'preheater is to beused. By providing lmeans for cleanin'v or removing the soot,

scalefor, thelike `from these' passages, the

' walls of the passages are rendered more durj able and hence gives the entire preheater a longer life'.

using the compressed air blast at a` point near the lower portion of the products of combustion assages, it is theaim'to pro vide diver g ranch or outlets 'from the main b ast pipe (w 'c is in front of the preheater casing) forinjectin the blast at angles into the products o? combustion passages and in injectin` these blasts, eddy currents of compreed air are created which act to thoroughly dislodge the accumulation of soot, scale and matter from the surfaces of the walls of the products 'of combustion passages. Certain portions of these walls are inclined or beveled, caused to be so formed 'due to the construction vof the air passages intervening the products of combustion passages, and by producing eddy currents, the soot and scale are easily dislodged, whereas should the blast be injected straight through the passages, a certain amount of the soot, scale. or the like would remain on the sloping surfaces and eventuallv cause a Wearing through of the metal wa ls. t

Moreover, the provision of theuompressed air blast at a location near the bottom of the passages of the preheater causes an 1n- `heater into a soot hopper, from which the soot may bearemoved in any convenient Also, the invention aims to provide improved air-cooled dampers operatively mounted'in the lower horizontal portions of the products of combustion passages for the purpose of controlling such products, it being possible to operate any oneor more of the dampers. In fact, the dampers are selectively operable so that one'A or more may be closed should a section become defective.

It is to be borne in nmind that this preheater is adapted for use in connection with boiler furnaces of large capacity where superheat flues are employed and where forced draft apparatus are used for sending a draft through super flues, the principal aim being to preheat this forced draft, hence the foregoing comparison between tlie Old appliances and the present construction herein disclosed.

It is tobe understood that the particulars se't` forth, shown in the drawings and p claimed.

In the drawings: Figure 1 isa view in improved super perspective of the frames of the seo-- reheating apparatus cons lstructed in accor ance with the invention.

' tions and illustrating the \arrangement and construction of the plates or walls forming the air passages and thelproducts of combustion passages and illustrating a modified construction of air blast for cleaning the products of combustion passages. Y

Figure 3 is an enlarged section al view on line 3-3 of Figure 1 near the top of the preheating apparatus, showing the construcvtion and arrangement of the compressed air blast.

Figure 4 is a sectional view on line 4-4 of Figure 1, showing the construction and arrangement of the compressed air blast near the bottom of thepreheating apparatus.

Figure 5 is an enlarged detail 'perspective view of one end of the comprssed.air blast at the top, showing the arrangement of the pipes.

Figure 6 is a sectional view on `line 6-6 of Figure 2. i. M

Figuref7 is an enlarged sectional -view of parts'of the air and products of combustion passages, showing the alternate protuber- '25 ances or buttons which act to prevent undue collapsing of the passage walls.

Figure 8 is a perspective View of a part of one of the front plates.

Figure 8a is a detail view of one of the front plates 16, more clearly showing the nuts 19 and 20.

Figure 9 is adetail view of'one form of spray nozzle, sucli as shown in Figures 1 and 5, but showing the openings 43 instead of the v branch nozzles 44.

' Figure 10 -is an enlarged perspectiveview of one'of the units, showing the cutsor slits 22 for the reception of the platesf2`6 more clearly shown in Figure 6.`

Figure 11 isa sectional viewV through one `of the sections of the preheater and a portion of adjacent section, showing the inlets for the cold air. Y

Figure 12 is a sectionalviewv transversely tof the preheater showing the outlets for the cold air passages.

Figure 13'is'a vertical0 sectional view of a preheater modified to that disclosed in Figure 6, and.wherein the unitsare curved' at their upper and lower `rear portions, with a'modiiied form of air blast device disclosed.

Figure 14 is a view iii elevation of the form of 'door shown in Figure 13.

Referring tothe drawings, 1 esignates the base of the preheating appara us Awhich may be any proportions and any shape suitable for the plant with which the apparatusis r,tobe used. This base is constrpcted preff erably of plate metal, though other material. may be used, and preferably the lower part has its longitudinal walls converged downwardly, providin a -suitable hop er 2f for the soot and sca e.` The rear wa l of the hoppermay be provided with any suitable 65. mea'ns, such as dpors or theI like 3, through j Y A is laterally extended, a ording an extension heater 13 for the forced air draft.

which access ,may be had to the hopper for thev purpose ,ofv conveniently removing the soot and scale,

Adjacent the upper art 'of the base 1, it 70A 4 which may be any pro ortions and any shape. This lateral extension is slib-divided by the plate metal division wallsl, causing products of combustion passages 6 to be formed.` The extension 4, has a marginal` 7.5 terminal ange 7 which may be bolted or otherwise secured to the/products of combustion fines from the furnace forthe purpose of carrying olf these products to the stack. However, these products of combustion in passing to the stack act to preheat a foced draft, as will be hereinafter lunderstoo I Mounted in the passages 6 are air cooled dampers 8, the `journals 9 of which have lateral arms 9a which areaconnected by a bar 9b provided with .a handle at one end so that ally the dampers may be operated simultaneously. The construction of these 'dampers constitute the subject-matter of a co-pending application filed the 22nd day of May, 1924, ,whose Serial Number is 715,139, allowed October 3, 1924, which has matured into a patent issuedJune 23, 1925, Patent No. 1,542,989, and it is to be understood that such construction of dampers may be'used inv other l`places than herein disclosed. xItis obvious that when it is desired to remove a section of the preheater for repairs, the damper which controls the products of combustion passing through the products of combustion passages of the section may be closed. This may be done by disconnecting the arm of the journalr ofthe damper whichis to be' closed from the operating bar 9b by removing the connecting bolt. Obviously, the other vdampers may be op(ened and permit the preheater to operate as usual. \The lower portion of the hopper 2 is provided with `afterminal marginal flange 10' which may be bolted to fa base or foundation for the purpose of supporting the preheater in proper position. Thev upper part of Vthe base or hop er 2 has a marginal flange 11 which may e bolted, rivetedor otherwise secured at 12 to the fnarginal flanges of the removable sections of the smoke flue which, in the present instance, constitutes the pre- This preheater comprises a plurality'iof sections 1 4 and each section .contains a plurality of 'units 15. Each" section also consists of a frontiplate v16 which is marginally. flanged, as at 17, and-cut toy provide an, opening, 18. Referring to Figure 8`of the drawings v(wherein a detail view of the-front plate is disclosed) ,1 it will be Seen thatthe front plate is` cut,-`as' at 19, ina transverse directionfand then in a vertical direction, 'as

ends of the f jacent the top Y l 60 Jthereof while similar cuts 28 are formed at upwardly and the other downwardly to pro-` vde flanges 24. The portionsof the marginal flanges lpat the longitudinal edges of the front plate are outwardly bent and are riveted together, that is, betweenadjacent outwardl bent flanges 21.

Secure on the flanges 24am metal plates 25 which are interposed between the outwardly bent flanges 17 of the front plates. The plates have vertical flanges which ex-y tend downwardly and upwardly, that is, the flanges of the plates 25`at the lower portion of the 4frames or boxings extend downwardly 25 and the flanges of the upper plates 25 extend upwardly. These plates have their portions 26 secured by welding or otherwise inthecuts 22 of the opposed plates or walls 23 of the units 15:. In tearing down a sec- 30 tion for the purpose of repairing a unit, 1t is necessary to sever the welding or other connection of the parts 26 from the cuts22 whereby the front plate may be removed, 1n which case the units of the sections may be removed and plates similar to the fr ont plates installed for the purpose of closing thepassages of the adjacentsection. However, it is not necessary to install subst1tute plates for the reason that the division walls 5, as in Figure 3, may extend the full height of the preheater which would prevent the "products of combustion from passing into Athe furnace or boiler room. By the provision of the plates 25, a frame or boxing is d provided around the opening in the front plate, reinforcing the opening, and since the flanges 21 are outwardly disposed, they afford means tocwhich the forced air flues may be secured by riveting or otherwise, as

n Figures 6 and 13.

. In order to Vconstruct the units,the' opposed walls of each unit are dished in opposite directions. The margins of the dished parts of those walls or lates slope or bevel toward eachother, as s own at 27, and the portions of the plates beyond the bevels or vsloping parts are preferablyl welded. It will be noted that the cuts 2 2 are positioned ad' of the preheater at, one side lthe bottom on the opposite side of the preheater, there being back plates 29 similar to "the frontplates, hence provided Vwith open-v.

ings 30 mth-surrounding frames consisting 6I Aof outwardly extending flangesjand plates 31. In other words, the backplates are cut the same as the front plates and the plates 3l are fixed in position similar to the plates 25. The plates 31 are welded in the cuts 2 8 and riveted t'o the hflanges which are cut and bent from the back plates 29.

In Figure 13, the back plates 29a are solid throughout the height of the preheater and, furthermore, the front lower portions of the unit walls have cuts 28*L to receive plates 31EL similaito.y` thel platesll in Figure 6. Re-

ferrug to Figure 13, it will be noted that i the upper and lower rear portions of the units are rounded off' so'that the forced air draft through the units will traverse'a curved course, thereby preventing pocketingv n of the air in the corners of the units as in Figure 6. However, the pocketing of the air in the upper and lower diametrical corners of the units in Figure 6 enables the air to be more thoroughly'heated as it is detained at these points, therefore will receive agreater amount of heat. n

Should it be desired to remove thecback plates instead of the front plates, it is necessary to sever the welding where the plates 31'or the plates 31a are secured in the cuts of the units. An air draft flue 32 is provided as in Figures 16 and 13, for carrying off the heated fresh air, and such flue 32 has connected to it, as at 3,3, as in Figure 6,

a flue 33a which may conduct the heated air I -their upper ends, as at 35, and the front and back plates 16, 29 and 29 are flanged at their upper ends, as at 36, affording means -for attaching by welding or riveting suitable fines 36l for carryingJof the products of combustion to the stack.A These flues 36 are also provided with air cooled dempers 36", similar in construction to the dempers' 8, with the exception that the dempers 36b are larger. When a section of the preheater is to be removed for repairs, the damper 36 of the section to be removed is closed. This may be accomplished byJdisconnecting the arm 36d from `the operatingbar 36S. ,Obviously, the remaining dampers may be closed or opened at Referring to Figures land 13, it will` be noted that a compressed airv blast device 37 is mounted inthe flue 36. Referrin to "Figures 1 and 13, the compressed air b ast device 37 is connected to .almain pipe 38 which is dissed preferably in front of the preheater. Figurev 1, the main pipe exit-'down-through the passages.

` tubes 40* which have openings or orifices 43 which, as well as the oriiices 43 in Fig.

' tends horizontally Vwhereas in Figure 13, it

from the main pipe aire branchv pipes 39- extends vertically. However, projecting which have at their inner`ends terminal .transverse ipe sections 40 closed at theirv Eopsite en s.

pending fromthe pipe `sections 40 byV means of theconnectors 41 areA .pipes or tubes 42. The pipesv or tubes 42 are 1n arallelism.. as in Figures 1,13, and 9. owever, the pipes or tubes 42 in Figures 5 and. 13 have nozzles 44 while' the tubes or pipes 42 in Figures 1 andi 9 have openings or orilices-43which act lto inject sprays of air' downwardly through, the combustion passages formed between the units. The branch nozzles 44extend in directions `from the sloping surfaces of the dished parts of.

device 37 1s modi ed to that shown in Figures 1 and 13. In Fi pipe 38 extends vert1cally and -is connected to al drum 38d' hich is fastenedA in any suitable manner,greierably by straps, to the preheater.. Projecting from the drums are ure 9,A are positioned to direct 'the blasts of -air divergently so as to pass through the products of combustion passages and insure the removal of the scale and soot. The

pipes which `connect the main pipes 38 and 38 tothe pipes 40 and the drums 38d have valves 40" which maybe closed for shutting o the air blasts through ythe products `of combustion passa Connectedto the main pipes 38'in Figures Y1 and 13 and to the main" pipe 38c by means of valves 41's*l are vertical pipes 46which connect with compressed air blast devices employed in con nection with the preheater.V The compressed air devices 45,5as in Fi es 1, 2, 4, 6 and 13, consist of drums 45 w ch'have'branch nozzlesV 48 connected thereto( These branch nozzles 48 diverge and extend. through .the front' plates 'of the sections and act to inject sprays of compressed airintov the products As the sprays assages of the preheater. om the lower branches 48 are injected into the passages at points apof combustion proximating the. bottom orf-the preheater,

. heater, `assisting they, in additionto creating eddy currents in nthese passages, also act to produce an injector actionon the sprays directed down# wardly fromthe upper partv of' the pre- .materially inforcing the compressed f air downwardly and to thoroughdyJ remove thesootand scale. The eddy currents created where 'the branches 48 inject the compressed airinto the pasother words, the )structed in directidns res/2 and 6, the mamV sages act to remove the scale vfrom the s1op l ing surfaces of the passages.

The opposed walls of he umts 'aren lro- Y' vided vwith depressed buttons or protu rances 49. Certain of these'button's'x 'or procertain others in the lo posits V direction. Certain of those of the waills of the air passages engage, preventing the walls from collapsing toward j. each other, while lthose. which extend from'each other contact 'with adjacent unit, thereby preventing the air Atuberances are extended in one direction and 4similar protubeance's, onthe 'walls .of an i passage walls fromjcollapsing away from v eachother. In. this latter case, the walls of the` products of combustion passa es" are v preventged" from collapsing inwar ly. In

ofA staggered relatipn, hence providing umts fora section, of whlch the walls are prevented from distortion due protuberances are con'- to defects caused from the collection of corf rosion and the like.1 Theseprotuberances Vpermit of a more complete passage of air from the forced air draft andv also a more complete passage oi? the products of -combus# tion, the latter acting to heat the former which is subsequently. injected intol aboiler furnacebeneath the lfire-bed, the primarypurpose being to facilitate the more thorough combustion'of the fuel.

- '/lhe frontplate of each ctlon of the 'fine .l

unit or preheater is provided with u per and lower inspection openings 50 close by the doors 51.v Obviously, the doors may be 'opened to permit` of inspection of the products of combustion passages in order to ascertain any defect that may have occurred due to the collection of soot and scale and should there be any defects, it is possible to tear down a section and permit of the reairl of the units 15. Also, inspection may e made Jfor the purpose of determining s when to turn on the compressed air blast. However, it is possible to permit the comressed air blast to operate Acontinuously to lnsure the prevention of the collection of soot and scale. This compressed air blast,

however, need not operate to itsQull capacity. Y ,f v

s Referring to Figures l and 6, it will be noted that the inspection doors are held `closed by transverse bars 50"V which are hinged to swin horizontally when the doors are opened.- e doors Amove with the bars. However, in Figures 13 and 14, the doors 51a are held closed by vertical bars 60 hinged to swing downwardly or upwardl by means of the pins 61.` In other wordst` e removal of either-.one ofthe pins wilfpermit the bar 60 to be swung upwardly or downwardly, allowing the door 51l to swing open td permit1 of inspection through the door openin s 50, As clearly shown" in Figures 4 an k\1, it will be noted that the products of combustion passages are wider than the air passages through the units. This feature is emphasized considerably in Figure? toiinsure thorough heating of the air passing through the umts. In other words, the greater .the area of heat as compared with the area of ilslhe air to be heated, the more the air receives eat. A

The invention having been set forth, what isclaimed is:

1. In a preheater for boiler furnaces, a

Y casing, means spaced therein forming products of combustion passages and air passages in alternating parallel succession, the walls between the. passages' having parts y of their margins deiected laterally formproducts of combustion and air passa es, the

latter at remote ends of the casing aving air inlets and outlets, the walls forming said y passages being marginally dished and inwardly from the dished 'margins having' rotuberances inthe fiat portions and extending alternately in opposite directions, thereby preventing collapsing of the walls, and air draft conductors connected to the casing and communicatingwith the pluralities' of air inlets and outlets respectively. y 3. In a preheater for boiler furnaces, a casing, means spaced therein' and `thereby forming products of combustion and air passages, the latter alternating with the former in parallelismftherewith and having air inlets at one side of the section to're- I ceive Aa, forced air draft, and air outlets at remote portions of the air passages, means connecting the air inlets of the air passages with a boiler furnace,tl1e forced air draft being preheated from the heat of the products ofl combustion, the walls forming said passageshaving protuberances therein ex i ss ' 'A casing,

tending alternately Ain 'opposite directions, thereby preventing collapsing ofthe walls.

4.A In a preheater for boi er furnaces, a means spaced therein and therebyforming rin parallel succession alternate roducts of combustion and air passages, the

atter being connected. to a forced air'di-aff supply at one side of the ,casing and rolvided with means for connection wit -a boiler furnace at the opposite side of saidcasin`g,`saidv casing being made up of a plurality of sections, each section capable ofbeing ruptured at its point of connection within the casing, whereby the sections may be removed and each section comprising a plurality of elements, which are capable of.y

rupture at their points of connection, perf mitting the elements to be removed, and thereby permitting any one of the sections to be removed for diminishing the size of the ,preheater casing. y

5. A preheater for boiler furnaces, comprising a casing, means spaced therein form-4 ing Iin parallel succession alternate products of combustion and air passages, the products of combustion passing through the former acting to heata forced air draft passing through the latter, means adjacent the top of the casing, and means adjacent the bottom of the casing, for injecting a compressed air blast into and through the products of combustion passages for carrying oif thesoot and scale downwardly;

' `64A preheater for boiler furnace s,`coin prising a casing divided into a plurality of sections, a plurality of elements vwith passages therethrough'spaced in and .compos-l ing each section, the spacing of the elements, together with the passages in the elements, constituting 'alternate products of combustion andair passages inspaijallelsuccession, the latter being connected with a forced air draft supply at one .side of the casing and provided with means for connection with a oiler furnace at the oppositesside ofsaid casing, the elements adapted to be ruptured at their points of connection withthe walls of said passages, thereby permitting any one of the sections to be removed for diminishing'the size of the reheater casing.

A.preheater^ or boiler furnaces, comprising a casing divided into a plurality of sections, a plurality' of elements withrpassages therethrough spacedin and composios ing each section, the spacing of the elements, together with ,the passages in the elements,

constitutin alternate products of combustion and airpassages in parallel succession, the latter being connected with a forced air draft supply at one side of the casing and, provided with; means for connection with a boiler furnace at the opposite side of said casing, the elements capable of beingrup-IV tured at their points of connection with the walls of said passages, thereby permitting any one of the sections to be removed for` diminishing the size of the casing, and vmeans adjacent the top ofthe casing .and

means adjacent the bottom'thereof for injecting' a compressed.' air blast into and throughthe produ s of combustion pas sages -for carrying he. soot and the scale downwardly. v l i '8; A preheater for'fboiler furnaces inlll lao

cludinga casing divided into' a plurality of sections, a plurality .of cellularv units in spaced relation andi composing each section,

the spacing of the units andtheir cell forming alternate products of combustion and air passages in p'a/rallel succession, eachl unit4 comprising opposed marginally outwardly dished Walls, said Walls inwardly of.

. the dished marginsbeing vfiat and the Walls beyond the dished margins belng marginally connected, certain parts of the remote portions dftheJ connectedmargins at the 'remote ends'- of each unit havingair inlets and air outlets.

9. A preheater for boiler furnaces includ- -ing a casing divided .into a plurality of sections, a plurality of cellular units -in spaced relation and composing eachv section, the spacing of the units and their 'cells forming alternate products of .combustionr and 'air passages in parallel succession, the

products of combustion passing through they forming alternate products of combustion and air passages in parallel successiomthe products of combustion passingtlirough the'l former passages acting to heat a forced air draft vpassing through the latter passages,

and means adjacent the -topof the casing and means adjacent the bottom thereof, for injecting a compressedl air blast into and through the products of combustion passages for dislodging the soot and scale, the compressed air blast injectingmeans near the bottom creating an injector action von passing through the latter, means adjacent the compressed air blast from4 above for creating a lthrough passage of the -coin-A pressed vair blast throughfthe" products of combustion passages.

11. A preheater for boiler'furnaces in-v cluding a casing divided into a plurality of sections', a lurality of cellulal`` units in spaced relatlon and composing each sectionv and thereby forming parallel alternate products of combustion Aand air passages, the products of .combustion vpassing-through the former acting to heat a forced air draft.

' the top of the casing and means adjacent the bottom, for injecting compressedl air blasts intand through the former passages for-dislodging the soot and scale, and al hopper atl the `-bottom of Athe casing for the reception of the soot and scale.

' 12. A preheaterffor boiler -furnaces including a casingdivided into a plurality of' spaced relation and composing each section and thereby forming parallel alternate products of combustion and air passages,

the products of combustion passing throughl the former acting to heat a forced air draft passing' through the latter, means adjacent the top ofthe casing andmeans adjacent the bottom, for injecting compressed air blasts into and through the former passages for dislodging the soot and scale, av compressed air Jblast injecting means near the bottom creating an injector action onthe compressed air blast lfrom above for creatf ing a'through passage of the compressedair blasts through the products of combustion passages, and a hopperat the bottom of the casing for the receptie/n -of the soot and Y scale-v. 1 3. A preheater for boiler Afurnaces including a casing divided into a plurality of sections, a, plurality of cellular umts in spaced-relation and composing each section and thereby forming parallel alternate products of combustion and air passages, the products of combustion passing through the former acting to heat a 4forced air draft passing through the latter, means adjacent the top of the casing and means adjacent the bottom thereof for injecting compressed air'jblasts into and through 'the former passages for dislodging the soot and scale, each compressed ,air blast means having diverging air injectingbranches fo cing the al blasts against the Walls of thproducts of combustion passages, creating-eddy currents for dislodging the soot and scale.

14. A preheaterA including a casing d1- vided intp a plurality of sections, a plurality .of cellular units in spaced relation and composing each4 section and forming therein a series of parallel alternate products ofcombustion and air passages, thegheat passing 4 through theV former acting to preheat a c 7 forced air draft passing througih the latter,

thepoinlts of 'connection ofsai units capable of being-ruptured, whereby said units may-be removably supported' in each sec- 'v tion, each section having aremovable front plate 4to permit the units to be removed. l

15. A- preheater including a casing d1- vided into a plurality of sections, a plurality` of cellular'units inspaced relation and co'mposing each section and forming therein a `series of parallel alternate products of com# f bustiony and air passages, the heat-passing 1 through the former acting to .Preheat a forced airA draft passing through the latter, lthe points of connection of said units'capable of rupture'at thpirpoints of connection in each section, whereby the sections are re-- movably adapted to be removed, each sectionhaving a Y,front plate capableiof rupture -y vat its point of connection inthe section to?.

permitithe units to be removed, there'mote sections', a plurality of Acellular units inl ends ofthe units,of which th'interiors con. B0

stitute the air passages, having means for attachment with forced air draft and boiler furnace iiues, thereby permitting the preheated forced draft to be conducted to the boiler furnace.

16. A preheater including a casing divided into a plurality of sections, a plurality of cellular units in spaced relation and composing each section and forming therein a series ofparallel alternate products of combustion and air passages, the heat passing through the former acting to preheat La forced air draft passing through the latter, said units capable of rupture at their points of connection in each section, whereby the sections are removably supported, each section having a front plate capable of rupture at its point of connection inthe section to permit the units to be removed, the remote en ds of the units, of which the interiors constitute the air passages, havingmeans for attachment with forced air draft and-boiler furnace fines, thereby permitting the preheated forcedv draft to be conducted to the boiler furnace, means for injecting compressed air blasts into the products of combustion-passages for blowing thesoot rand scale to the bottom of the casing, and a hopper at the/bottom of the casing to. receive the soot and scale.

17. A Apreheater `including a casing divided into a plurality of sections, a plurality of cellular units in spaced relation and composing each section and forming therein a series of parallel alternate products of combustion and air passages,l the heat passingthrough the former acting to preheat a forced air draft passing through the latter, the points of connection'pf said units capable of rupture at 'their points of connection in each section, whereby the sections are l removably supported,`each section having a removable front plate to permit the units to be removed, means at the' top and means near the bottom of the productsJ of combustion passages for injecting compressed air blasts into said passages .for blowing the soot and scale to Athe 4bottoni of the casing,

, the means atl the bottom creating an injector action on the` blasts from thel topto insure removal of the soot and scale, and a hopper at the bottom of the casing to receive the soot and scale.

.18. Avpreheater including a casing di- -vided into a 'plurality of sections, a .plu-

units `in spaced relation and rality of cellular section and forming therein composing each a' series of parallel alternate products of combustion and air passages, the heat 'passing through the former acting to preheat a forced air draft passing through-the latter, the-points of connection of said unitscapable of rupture at theirv points of connection in each section, whereby the sections are removably supported, each section having a spaces between the units ally beyond aplurality.A of

front plate capable of rupture at its point of connection in the section to rmit the units to be removed, and air b ast means at .the top and air blast means near the bottom, of the products of combustion passages for blowing the soot and scale to the bottom of the casing, said air blast means including blast injector nozzles which are divergent to direct sprays against the walls of the products of combustion passages, creating eddy currents4 to insure the removal of the soot and scale.

19. A preheater including a easing divided into a plurality of sections, a plurality of cellular units in spacedrelation and composing each section and forming therein a series of parallel alternate products of combustion and air passages, the interiors of the units acting as the air passages, the constituting the products of vcombustion assages, the op- `walls lof the units ing secured t0- gether marginally and having certain por'- tions of their margins at diagonall opposite points separated and `spaced, wit p ates above and below theedges of the separated and spaced portions, thereby formin openings leading to the air passages, sai i openings being iiues for conducting the preheated air toA a boiler furnace.4

A 20. A preheater including a casing divided into a plurality of sections',a plurality of cellular units in spaced relation and composing each section and forming therein a bustion and air passages, the interiors of the units constituting the air ssages, remote ends of the umts having inlet and outlet passages for a forced air draft, the walls of yond such dished margins and means for preventing collapsing of the, elements in either direction. p 21. A preheater including v a casing d1- vided into a plurality of sections, a plurality of cellular units in spaced relation and composing each section and forming therein a series ofparallel alternate products of combustion. and air passages, thev interiors of the units constituting the air passages, remote ends of the units having inlet and outlet passages for -a forced air draft, the wvalls of the elements being inwardly dished and being flat inwardly from such dished margins `and such dished mar s, means for` preventing collapsing of t e elements in either direction', and means for supporting the elements ineach section m 1 j. 2. A compressed air blast apparatus for products Ofcom connected to forced air draft.

parallel alternate products of comiio being secured together marginofthe casv ustion pas-*18D products of combustion and air pass the former alternating" with the latterin-I parallelism'l therewith having air inlets at one side of the casing for receiving a forced air draft, said inlets being connected with a boiler furnace, air out-lets at remote portions of the air passages, the forced' air draftl being preheated by the heat from the products of combustion, and means at remote portions of the products of combustion Ipassages for directing cleansing lluids therethrough to insure removing the soot and similar matter that collects in the passages. .l

2A. A compressed air blast apparatus for a pluralit of p oducts of com lustion passages, sai app atus comprising main supply pipes, one with branches locatedyadjacent the ends of the passages, the other r,with branches adjacent the sides of the passages in advance ofthe first set of branches, both sets of branches having spray outlets 'directed toward the walls of the passages creating a eddy currents, the currents of the latter branches creating an injector action on thev currents' .from the outlets of the former branches. g

25. In a preheater,"a series of cellular units arranged side by side in s acedrelation and their interiors forming air passages, the spaces between said units forming passagesfor products 'of combustion, air inf lets communicating with the interior ofl said cellular units, air outlets leading from said cellular units, Nan inlet beneath said unitsv for suppying products of'coinbustion to the spaces eating with the s aces between .the'units at the `upper vend t ereof, and means to inject ]ets of compressed air4 between said .units and against the walls thereof.

96. `In a preheater, a series of cellular units arranged' side by side in spaced relation and their 'interiors forming` air passages, the spaces between said' units formm passages for productsgofcombustion, air infets'oommunicatin with the interiorof said cellular.units,.a1r-outlets leadin from said cellular' units, an inlet beneat said units for products of vcombustion to the spaces tween the units, outlets communicatin with the s aces between the units at t e upper end t ereof, and means `said compressed air tween the units, outlets communi` at the top of said outlets for directing jets of compressed air downwardly between said units against the passages of the product o f combustion through the spaces between the units. i

27. In a preheater, aseries of cellular units arranged side by side in spaced relation and their interiors forming air passages, the

spaces between said unitsforming passages for products of combustion, air inlets communicating with the interior of said cellular units, air outlets leadin from said cellu-v lar units, an inlet beneat said units for supplying products of combustion to the spaces betweenthe units, outlets communieating with-the spaces between the` units at i the up er end thereof,l means at the top of vsad'out ets for directing jets of compressed air downwardly between said units against the passages of the roduct 'of combustion through the spaces' etween 'the units',"and

other means positioned below the last mentioned means for directing the jets of compressed air downwardly and across the lower parts of the Js aces between said units.

`28. Ina pre eater, a series of cellular units arrangd side by side in spaced* rela-f tionV and their Iinteriors forming air 'pas-v sages, the spacesbetween said units forming i passages for products of combustion, air inlets communicating with'the interior of said I cellular units, air.` outlets leading from said cellula;` units, an inlet beneath said units .for suplpying Aproducts of combustion to the spaces tween the units, outlets coinmiiiii-v` eating with the spaces between the units atv the upper end thereof,l and compressed air pipes extending horizontally in the central planes ofthe spaces between saidunits and having jet outlets in their bottom portions,- pipes being located above sai units.

29. In a preheater, a series' of cellular units arranged side byl side in spaced relation and their interiors forming air passages,

the spaces between said units `forming passages forproducts of combustion, air inlets communicating with i the interior .of .said cellular units, air outlets rleading from said cellular uni-ts, an inlet beneath said. units for supplying products ow combustion to the spaces between the units, outletscom- 'l municatingv l with the spaces between the units at the 'up r end tliereof, com ressed air pi tral anes of the' spaces between said units and aving jet outlets in their bottom portions, said compressed air pipes being located above said units, and other compressed air pipes located at the front of the lower portion of the heater and terminating'in nozzles directedv inwardly and downwardlyv @ouais-- into theA spaces between said units.'

30. In a preheater, a series of units 'arranged side by 'side in spaced relas exten ing horizontally in t e cenietsv tion and their interiors forming air passages the spaces between said units forming passages for products. of combustion, air in- "lets communicating with the interior'of said cellular units, air outlets leading from said cellular units, an inlet beneath said units for p supplying products of combustion to the spaces between the units, outlets communicating/with the spaces between the units at the'upper end thereof, compressed air pipes extending horizontally. in the central-planes p o the spaces between said units and having jet outlets in their bottom portions, said compressed air pipes being located above said units, and other compressed air pipes located -at the front of the lower portion of the 'heater and terminating in nozzles di-` rectedinwardly and downwardly into the' vspaces between said units, the last mentioned.

" tlierefrom'against the outer surfaces of the walls of said'units. Y I

31. ln a preheater, aseriesy of cellular units arranged side by side in spaced relation and theirv interiors forming-air passages, the spaces tween said units forming passages for againstthe passages of the products of combustion, air inlets. communicatin' with thev interior of said cellular units, air outlets leading from said cellular units, an inlet beneath saidunits forsupplying products of combustion to the spaces between the units, outlets..

communicating with the spaces between the units at the upper end thereof, means at the topv of said outlets for directing jets of com.- pressed air downwardly between said units between said. units forming passages foi'- combustion, air inlets communiproducts of 'eating with the interior of said` cellularv units, airoutlets leading from said cellular units, an inlet beneath said units for supplying products of combustion tothe spaces between the units, outlets communicating with the spaces between the units at the up-` r end thereof, .means at the. top of said outletsl for directing jets of compressed air downwardly between said units againstfthe passages of the product of combustion through the spaces`between the units, other means positioned below the lastmentioned means for directing the jets of compressed downwardly-andacross the lower partsaid units, and a soot' oi the spaces between hopper locatedbelow the'bottoin of 33; In a preheater, `a series of cellular arranged side fby side in spaced" relation-and forming air passages,

said units,

nozzles diverging to direct the air issuing forming airpassag, the

product of ccm-` hopper located' the air passages of the units,

capab be removed, the Y their connections in the spaces -between* saidv forming passages'l for products of combustion, air inlets communieating with the .interior of said cellular units,

air outlets leading from said cellular units,

an inlet beneath said units for supplying .pressed air pipes bein located above said` units, other compress air pipes located at the front of the lower portion of the heater and terminating in nozzles directed inward- 1yl and downwardly into the spacesbetween and a soot receiving hopper located below the bottom of said units.

34; In a reheater, a of cellular units arranged sfide by side'in spaced relation and spaces between said units forming passages for products of combustion, air inlets communicating with the interior of said cellular units, airl outlets leading from said cellular units, an inlet beneath said units for supplying products of combustion to the spaces between the units, outlets communicating with the s aces between the units' at the upper end t ereof, compressed air pipes extending horizontally in the central planes of the spaces between said units and avin jet outlets in their bottom portions, said c pressed air' pipes being located above said units, other 'plurality of' cellular units spaced side side and composing'each section, the spaces .between the .units constituting roducts of combustion "passages, the interiors of the units-constituting vair passages, airv inletsl and outlets leading to and extending from inlets at one end of the casing connecting with the roducts of combustion passages respective y, out` lets at the other end of the casing and communicating Witlithe products'o'f combustion passa es, respectively, the :sections being tion in the casing, wliereby the sections may units capable of rupture at 'I feach section. thereby rendering the sections capable of' disassem- 36. In a vpreheatei",I af .comprising a of ruptur'at other points of connecioo los

liza

v Loveno units constitute air passages, the fomer al temang with fthe imiter, aix` nletsond outlets eadmg to and rom remote endsof the air passages `oi" he uns9 passage commum-eating wish the productswo combustion passages of each seamen fo conduct the produots of combustion ftherethrough a passage leang 'hom the` products of combustion passages of eeoh seotlon to comfy 0H the prodnots of combustion, theseetons and the units capable of rupture at 'the points of their oomleotioos in the casing and in the sections, whereby the sections and the units may be disassembe, emimeans in the indvdua passages exendmg to and *hom and communicating with the products of eombusion passage im shutng off the products of combustion when may one or more of the sections are disassembled. 5

im witness whereof the nvenors signa.- ture is hereunto exed.

WMJMAM M. Cosmesi, 

